Details

Autor(en) / Beteiligte

• Kaiser, Maria
• Günnemann, Stephan
• Disse, Markus

Titel

Regional-scale prediction of pluvial and flash flood susceptible areas using tree-based classifiers

Ist Teil von

• Journal of hydrology (Amsterdam), 2022-09, Vol.612, p.128088, Article 128088

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2022

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• •Literature review on explanatory features used in flash flood modeling.•Comparison of three tree-based classifiers for a large investigation area.•Use of 11 spatially distributed and 6 catchment-related explanatory features.•Model interpretation using model-specific and model-agnostic methods. Flood events triggered by heavy rain, such as pluvial and flash floods, are a common threat worldwide. However, it is usually not known which areas and cities are particularly vulnerable to flooding caused by heavy rain. To enable regional-scale susceptibility assessment, we developed a novel methodology based on tree-based classifiers that considers both spatially distributed and catchment-related influencing factors. The performance of the developed methodology was evaluated using the region of Bavaria (Germany). For the case study area (70,500 km2), we trained a Random Forest (RF), a Gradient Boosting Decision Tree (GBDT), and a CatBoost model (CB) using 1,864 flood and non-flood locations and 11 spatially distributed and six catchment-related influencing factors. Regarding performance metrics, all three models performed equally well (CB: AUC = 0.819, RF: AUC = 0.816, GBDT: AUC = 0.813), with the CatBoost model performing best. When modeling large areas, it proved critical to account for low sample density by ensuring (i) a homogeneous spatial coverage of the study area and (ii) the representation of the major landscapes in the training and test set. In addition, we propose an overall susceptibility score for cities based on the susceptibility map generated, which can be used to prioritize cities for detailed investigations. Those responsible for spatial planning and flood risk management can apply the proposed methodology to obtain a pluvial and flash flood susceptibility assessment for large territories.